As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to these users is an information handling system. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may vary with respect to the type of information handled; the methods for handling the information; the methods for processing, storing or communicating the information; the amount of information processed, stored, or communicated; and the speed and efficiency with which the information is processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include or comprise a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
A computing system will typically include some form of temporary information storage medium, such as random access memory. In come computing systems, the amount of memory included in the information handling system may be on the order of gigabytes. As memory size increases, the likelihood that part of the memory will either be manufactured defective or become defective over time increases dramatically. If left unmanaged, the presence of defective memory cells, regardless of their size, can cause the information handling system to fail, which can initiate an abrupt end to the current operation of the information handling system, resulting in the loss of critical data, or can prevent the information handling system from starting up altogether.
As computing systems continue to evolve and computer technology advances, the operational relationship between the CPU and memory becomes more significant. Many attributes of modem systems (specifically the introduction of multi-core processors and virtualization in general) are forcing an ever-growing memory footprint. Consequently, not only is system memory growing to be a much more substantial percentage of the overall solution cost, but the impact of erroneous behavior in the memory can have a much more adverse effect on the life cycle expenses associated with the computing system.
Traditionally, embedded error correction schemes have successfully been used to avoid “crashes” on a single bit error and to detect multi-bit corruptions. However, as memory geometries become smaller and memory size grows larger, it is necessary to add another level of service protection that is quickly available and resident on the memory module itself. The successful operation of the system in a PC architecture depends on certain memory areas not being defective. For example, even in an advanced server system that includes 128 GB of memory, it is critical that certain memory regions such as the interrupt vector locations, Basic Input/Output Systems (“BIOS”) data area, and the 64 KB region at F000:0 address space contain no defects.
There are a variety of methods that may be employed to track or otherwise indicate the presence of a known memory error. As a result, in instances where the presence and condition of a defective or damaged memory block is known, it becomes imperative that early BIOS Power-On Self Test (“POST”) processes be made capable of tolerating memory defects. Specifically, it is desirable to allow the POST processes to successfully complete the POST initialization process without crashing, despite the existence of the known memory defects.